• A minicomputer system has been developed to digitize and store visual field data. In 110 cortiocosteroid-nonrespond-Ing subjects aged 10 to 75, the area of the l4e and l2e isopters and of the blind spot changed linearly as a function of age. Within this population the same visual field parameters were randomly distributed with respect to intraocular pressure. In 32 cortiocosteroid responders (increase in intraocular pressure to over 31 mm Hg after topical administration of corticosteroids) with normal visual fields, the central visual field area (l2e isopter) was reduced as a nonlinear function of IOP. Increases in IOP in excess of 8 mm Hg were required to produce significant mean reductions in central visual field area.